Maritime New Zealand says 737 tonnes of oil has now been pumped off the Rena on to the bunker barge Awanuia.
Pumping temporarily stopped onboard the stricken container ship on Wednesday while equipment being used in the oil transfer is repositioned inside the vessel's port tank.
Maritime New Zealand says only 35 tonnes of fuel oil remains to be pumped out of the port number five fuel tank, which initially held 772 tonnes.
The authority says a plan to use existing pumps on board the Rena to transfer oil from the ship's settling tanks into the port tank didn't work because of what it thinks is damaged pipework.
Salvage unit manager Bruce Anderson says alternatively a hose system will be set up to pump oil from the settling tanks onto the tug boat Go Canopus, which will be a slower method.
It's three weeks since the 47,000-tonne ship grounded on the Astrolabe reef, 22km from the Tauranga coast.
